Impulse generator



April :23, .1935." Rf. c.-couPl AND I 1,998,446.

IMPULSE GENERATOR Filed 0613. 2, 1954 '6 n -E-V W- Patented Apr. 23, 1935 i orsi nvrPrmsE GENERATOR Richard C. Coupland, Norfolk Applicationrctober 2, 1

unites states Army, Va. v g 934., serialNo. '74.6533

s ciaims.- (o1. ssi-2v) i lorante, meer the act @March s, issajas 'j amended April 30, 1928; 370 O.A G.,757)

employed in a synchronized control system such as is used-to control thefiring'of machine guns between thebla'de's of arotating propeller of air-'- The. purpose `oi this invention is to provide a compact 'impulse .generator in whichV the field member of an electrical unit is employed to releasablyholdan impulsetransmitting member im movable; 1 1 f1 iy M v 2A further object is to provide a mechanical arrangement for moving the field member out of engagement .with the impulse transmitting member; 7 Z'With2the foregoing andv other objects in View, the inventionresides in `thesnovel arrangement and combination Vof "parts and in the details of construction hereinafter described and claimed, it being Vunderstood that changes in the precise embodiment of theinvention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

. illustrated A practical embodiment of the invention is in the accompanying drawing, wherein:

Fig. l is a view in side elevation of a gun control assembly.

Fig. 2 is a longitudinal sectional View of the impulse generator showing the eld casing in engagement with the cam follower.

Fig. 3 is a similar view with `a eld casing disengaged from the cam follower.

Fig. 4 is a plan view of Fig. 2 with part of the top broken away.

Referring to Fig. `l the gun control assembly consists of an impulse generator A connected to atrigger motor B by means of an impulse cable and cable housing C. Y Y Y 'I'he impulse generator unit is arranged to constitute a compact integral part of the airplane engine synchronized thereto during or after assembly and it consists of a housing 5 in-which is mounted a driven shaft B having a gear 1 by which it receives its energy from a driving shaft 8 of the engine. The shaft 5 is supported by antifriction bearings 9-9 and carries a cam lll positioned in the lower portion of the housing 5. The shaft rotates at a speed ,to give acam impulse for each blade of the propeller of the airplane engine. When the shaft Eis driven at the same speed as the propeller the cam will have the same This invention relates to'an impulse generator number of lobes asY there are blades on the propeller while Ythe number of lobes will be doubled if the shaft is driven' at half of the propeller speed. Y

A cam follower Il arranged Yparallel to the Y g driven or cam shaft 6 is slidably mounted in the housing 5 and has a foot i2 at its lower extremity which carries a roller I3 adapted to engage thev lobes of the cam IG. Threaded in the other'end of the follower is a plug i4 in which is secured the Vimpulse cable vI5 leading to the trigger motor B. The cable is sheathed in a tube .I6 which is secured in a socket l1 removably held in placeiby a nut vI8 threaded to thehousing."

An electrical control unit within the housing 5 comprises an varmature I9 and cornmutator 29 carried by the driven shaft 5 anda magnetic field 2l carried by acasing 22-mounted on antifriction bearings 23-23 and carrying one of thebearings 9 of the shaft 6. `The eld2l is ofthe permanent magnetic type or as shown of the .self-- eXcited type under excitation at all times so that thetime'lag required'to build up a current'fiow in thefclosedcircuit will he a minimum;L The casing 22 carries brushes 24-24 wiping the commutator 20, and conductors 25-25 lead from the brushes through posts 26-25 to a switch 2T on the control stick 28 of the airplane.

When the` switch is closed it causes an increase in the current flow and a consequent increase in the magnetic pull between the armature and the field. This increase is suiiicient to rotate the casing 22 against the action of a coilspring 29 whose ends are respectively attached to the cas- '.ingZZ and to the housing 5. 'I'he rotational dis- Vplacement-of the casing is limited by cooperatis angularly displaced out of the path of movement of the arm 32 land the cam follower is free to reciprocate. When the switch is open the casing 22 is counter-rotated by the spring 29 to .place the cam sear in engagement with the arm and-again hold the cam follower immovable.

ing 5 includes a rack 39 meshing with the pinion. A cable 40 attached to the slide is actuated by a hand lever 4| placed on the control stick V23 of the airplane. 'Ihis arrangement provides a mechanical operating mechanism for retracting the slideand causing the casing 22 to be rotated to disengage the cam Sear 34 from the arm of the camvfollower. The spring 29 restores the parts when pressure on the hand lever 4I is relieved. An additional spring 42 may be provided to supplement the action of the spring 29 and is preferably confined between the slide 38 and a socket member 43 which is threadedly secured to the housing 5. .Y

The trigger motor unit B,'which forms the subject of a separate application, includes a spring 44 which is generally common to this type of mechanism as seen in my prior Patent 1,770,125 of July 8, 1930. This spring acts on a-slide 45 which recevies the impulse transmitted by the cable l5 and the spring serves to restore the slide when the cam follower is not acted on by the cam IB. When the cam follower is depressed by the cam I0 the cable l5 retracts the slide 45 and 'compresses the spring 43.

I claim:

1*. In a synchronized mechanism ,an impulse generator including a housing,'a driven cam shaft in the housing,` a cam follower in the housing, an armature on the cam shaft, a casing rotatable about the axis of the cam shaft, al magnetic field on the casing, an electrical circuit between the armature 'and casing and including a switch, a spring for counter-rotating the casing, a cam on the casing engageable with the cam follower Y to hold it immovable, a pinion on the casing, a

rack slidably mounted inthe kcasing and meshing with the pinion, vand means for retracting the rack. i. Y'

2. InA a synchronizing mechanism, an impulse generator including a housing, a driven cam shaft in the housing, a cam followerin the housing, an 'armature on the cam shaft, a casing rotatable about the axis of the cam shaft, a magnetic field on the casing, an electrical circuit between the armature and casing and including a switch, a spring for counter-rotating the casing, a cam on the casing engageable with the cam follower to hold it immovable, and means for mechanically rotating the casing out of engagement with the cam follower.-

3. In a synchronizing mechanism, an impulse generator including a housing, a driven cam shaft extending into the housing, a cam follower in the housing, an electrical unit within the housing including an armature driven by the cam shaft anda rotatableY field member, a spring for the field member, means on the field member engageable with the'cam follower to hold it immovable and means for mechanically rotating the field member;

4. In a synchronizmg mechanism, an impulse generator including a housing, a driven cam shaft extending into the housing, a cam follower in the housing, an electricalunit withinthe housing including an armature driven by the cam shaft and a rotatable field member, a spring for the field member, means on the eld member engageable'with the cam follower to hold itimmovable.

' 5. In a synchronizing mechanism, the combination with a driven cam shaft and a cam follower, of an electrical unit including'a rotatably mounted field member releasably engagingthe cani follower to hold it immovable, a; spring normally holding the eld member in'position to engage the cam follower, a pinion on the field member and a rack meshing with' the lpinion.

6. In a synchronizing mechanism, the combi nation'with a driven cam shaft anda cam follower, of an electrical unit including a rotatably mounted Vfield member releasably engaging the cam follower to hold it immovable, a spring normally holding the field member in position to engage the cam follower, and means for mechanica-ly rotating the field member out of engagement with the cam follower.

RICHARD c. coUPLAND. 

